obexd: fix canceling queued transfers
obexd: fix canceling queued transfers

The Cancel() method in the D-Bus api should also abort queued transfers,
which should just be removed from the queue.

pkarasev3/bluez,pkarasev3/bluez,silent-snowman/bluez,mapfau/bluez,mapfau/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,mapfau/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,ComputeCycles/bluez,pkarasev3/bluez,pkarasev3/bluez,silent-snowman/bluez,ComputeCycles/bluez,silent-snowman/bluez